The National Science Foundation established the Cell Culture Center in 1974 and has continued to support it for the purpose of providing large quantities of animal cells and their products to scientists lacking facilities to produce their own cells. As planned from the beginning, NSF funding is now being phased out. In the past nine years, the Center has completed more than 300 projects involving large-scale animal cell production. Much of the material has been supplied to researchers outside the New England area, almost all of whom have NIH support. Since NSF funding will not continue after 1986, we are seeking partial support for the Center from NIH. We feel that this support will be cost effective since large-scale cell and virus preparation can be handled much more efficiently by the Center than by individual investigators. Over the next five years, the Center plans to meet or exceed its current annual production rate of a trillion cells. In addition, extensive efforts will be made to improve the services provided by conducting research in the following areas: (1) Reduction in serum requirements for cell production; (2) Development and application of microcarriers and other cell production systems; (3) The use of computer technology and instrumentation to optimize conditions for cell production.